import uuid

from django.contrib.auth.models import User
from django.db import models

from django.urls import reverse
from datetime import date


# Create your models here.
class Genre(models.Model):
    """Model representing a book genre."""

    name = models.CharField(max_length=20, help_text='Enter a book genre (e.g. Science Fiction)')

    # def __init__(self):
    #     name = models.CharField(max_length=20, help_text='Enter a book genre (e.g. Science Fiction)')
    #     super(Genre, self).__init__()

    def __str__(self):
        """String for representing the Model object."""
        return self.name


class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey('Author', on_delete=models.SET_NULL, null=True)
    summary = models.TextField(max_length=1000, help_text='Enter a brief description of the book')
    isbn = models.CharField('ISBN', max_length=13,
                            help_text='13 Characters <a href="https://www.isbn-international.org/content/what-isbn">ISBN number</a>')
    genre = models.ManyToManyField(Genre, help_text='Select a genre for this book')
    language = models.ForeignKey('Language', on_delete=models.SET_NULL, null=True)

    # class Meta:
    #     ordering = ['title']

    def __str__(self):
        '''String for representing the Model object.'''
        return self.title

    def get_absolute_url(self):
        return reverse('book-detail', args=[str(self.pk)])

    def display_genre(self):
        return ','.join(genre.name for genre in self.genre.all()[:3])

    display_genre.short_description = 'Genre'


class BookInstance(models.Model):
    id = models.UUIDField(primary_key=True,
                          default=uuid.uuid4,
                          help_text='Unique ID for this particular book across whole library.')
    book = models.ForeignKey('Book', on_delete=models.SET_NULL, null=True)
    imprint = models.CharField(max_length=200)
    due_back = models.DateField(null=True, blank=True)
    LOAN_STATUS = (
        ('m', 'Maintenance'),
        ('o', 'On loan'),
        ('a', 'Available'),
        ('r', 'Reversed')
    )
    status = models.CharField(max_length=1,
                              choices=LOAN_STATUS,
                              blank=True,
                              default='m',
                              help_text='Book availability', )
    borrower = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, blank=True)

    @property
    def is_overdue(self):
        if self.due_back and date.today() > self.due_back:
            return True
        return False

    class Meta:
        ordering = ['due_back']
        permissions = (("can_mark_returned", 'Set book as returned'),)

    def __str__(self):
        return f'{self.id} ({self.book.title})'


class Author(models.Model):
    first_name = models.CharField(max_length=100)
    last_name = models.CharField(max_length=100)
    date_of_birth = models.DateField(null=True, blank=True)
    date_of_death = models.DateField('died', null=True, blank=True)

    class Meta:
        ordering = ['last_name', 'first_name']

    def get_absolute_url(self):
        return reverse('author-detail', args=[str(self.pk)])

    def __str__(self):
        return f'{self.last_name}, {self.first_name}'


class Language(models.Model):
    name = models.CharField(max_length=50,
                            help_text="Enter the book's natual language (e.g. English, French, Japanese, etc.)")

    def __str__(self):
        return self.name
